The present invention relates to a high-capacity memory accessible by a number of external agents (particularly processors), having a data capacity possibly exceeding the addressing capacity of each of the said agents, and particularly suitable for use on multiprocessor systems. A need is generally acknowledged for combining high computing power with the ability to handle large streams of in-coming and out-going data, particularly in applications involving complex real-time processing (e.g. image processing, pattern and voice recognition, artifical intelligence and scientific computation in general). The formation of high-computing-power multiprocessor systems poses various problems, including addressing capacity of the memories, and rapid data transfer between different memory groups.